The disclosure of the present disclosure to be disclosed in this specification relates to a friction plate and a hydraulic transmission apparatus.
A friction plate of this type has been hitherto proposed that includes a base plate having an annular plate shape and a plurality of friction members fixed to at least one side of the base plate, at predetermined intervals in a circumferential direction of the base plate, and that is configured to press the friction members into contact with a counterpart plate (another friction plate) opposite to the friction members when the clutch is engaged (e.g., see Japanese Patent Application Publication No. 2002-156021). After each friction member of this friction plate is formed by punching, a step portion is formed by compression molding at each end of the friction member in the circumferential direction in order to remove edges in the circumferential direction resulting from punching. Thus, scraping off of an oil film by remaining edges can be prevented, so that a sufficient oil film is formed between the friction plate and the counterpart plate to stabilize the drag torque.